textproduct: Rapid City

KEY MESSAGES

- Hot temperatures continue through the weekend with elevated to near critical fire weather conditions.

- Isolated thunderstorms Thursday and Friday - mainly Black Hills and northeast Wyoming - with scattered thunderstorms this weekend across the entire area.

- Unsettled and cooler next week.

UPDATE

Issued at 1015 PM MDT Wed Jul 15 2026

A couple of isolated showers/storms have tried to develop along a sfc trof currently located across NE WY this evening. Can't rule out isolated shower activity overnight across NE WY but confidence too low to include in PoPs at this time. Otherwise, the extended period of very hot conditions continues to be the main forecast concern over the next few days. Highs in the upper 90s to 100s expected across much of western SD and northeastern WY through the weekend as upper level ridge dominates the upper level pattern into the weekend.

DISCUSSION

(This Evening Through Wednesday) Issued at 1243 PM MDT Wed Jul 15 2026

High pressure continues to be centered over the Central Great Plains with water vapor imagery showing moisture streaming into the Desert Southwest up into the Rockies. At the surface, an area of low pressure is centered over southeast Montana with a warm front extending through southern North Dakota, a lee trof along the Bighorns, and a cold front extending into northwest Wyoming. Temperatures at 19Z are in the 90s, with a few spots around 80 in the higher Black Hills. Winds are generally south to southeast at 5 to 15 mph.

The cold front will slowly slide into the forecast area tonight as the surface low pushes into southwestern North Dakota and eventually into south-central North Dakota by Friday morning. The main impacts with the cold front will be limited. Winds behind the front will be northerly, high temperatures will be a degree or two cooler, and there will be a chance for afternoon and evening thunderstorms.

Low level moisture begins to increase Thursday morning as the upper ridge begins to slowly break down. The increase in moisture combined with an increase in instability may allow for isolated thunderstorms behind the cold front on Thursday and Friday. There will be greater chances for storms this weekend as the upper ridge shifts eastward, monsoonal moisture streams into the area, some small vorticity maxes move through the flow, and modest ascent along the frontal boundary.

Models differ slightly on how fast the upper ridge collapses and the positioning of the surface fronts this weekend. However, the overall pattern will lead to a chance for scattered storms this weekend, with unsettled weather and cooler temperatures next week.

AVIATION

(For the 12Z TAFS Through 12Z Friday Morning) Issued At 514 AM MDT Thu Jul 16 2026

VFR conditions expected through the period. Isolated/scattered gusty thunderstorms may occur over the Black Hills/northeastern WY this afternoon/evening, but not enough confidence they'll hit the TAF sites, so have not introduced to the forecast.

UNR WATCHES/WARNINGS/ADVISORIES

SD...Heat Advisory until 9 PM MDT /10 PM CDT/ this evening for SDZ001- 002-012>014-025>027-030>032-041>044-046-047-049-072>078. WY...Heat Advisory until 9 PM MDT this evening for WYZ054>056-058>060.